<header>
    <nav class="navbar navbar-expand-md navbar-dark fixed-top bg-dark">
        <a class="navbar-brand" href="#">控制台</a>
<!--        <button class="navbar-toggler d-lg-none" type="button" data-toggle="collapse" data-target="#navbarsExampleDefault" aria-controls="navbarsExampleDefault" aria-expanded="false" aria-label="Toggle navigation">-->
<!--            <span class="navbar-toggler-icon"></span>-->
<!--        </button>-->
<!---->
        <div class="collapse navbar-collapse" id="navbarsExampleDefault">
<!--            <ul class="navbar-nav mr-auto">-->
<!--                <li class="nav-item active">-->
<!--                    <a class="nav-link" href="#">Home <span class="sr-only">(current)</span></a>-->
<!--                </li>-->
<!--                <li class="nav-item">-->
<!--                    <a class="nav-link" href="#">Settings</a>-->
<!--                </li>-->
<!--                <li class="nav-item">-->
<!--                    <a class="nav-link" href="#">Profile</a>-->
<!--                </li>-->
<!--                <li class="nav-item">-->
<!--                    <a class="nav-link" href="#">Help</a>-->
<!--                </li>-->
<!--            </ul>-->
<!--            <form class="form-inline mt-2 mt-md-0">-->
<!--                <input class="form-control mr-sm-2" type="text" placeholder="Search" aria-label="Search">-->
<!--                <button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button>-->
<!--            </form>-->
        </div>
    </nav>
</header>